Generic Simulation Approach for Multi-Axis Machining, Part 2: Model Calibration and Feed Rate Scheduling

2002 ◽  
Vol 124 (3) ◽  
pp. 634-642 ◽  
Author(s):  
T. Bailey ◽  
M. A. Elbestawi ◽  
T. I. El-Wardany ◽  
P. Fitzpatrick

This is the second part of a two-part paper presenting a new methodology for analytically simulating multi-axis machining of complex sculptured surfaces. The first section of this paper offers a detailed explanation of the model calibration procedure. A new methodology is presented for accurately determining the cutting force coefficients for multi-axis machining. The force model presented in Part 1 of this paper is reformulated so that the cutting force coefficients account for the effects of feed rate, cutting speed, and a complex cutting edge design. Experimental results are presented for the calibration procedure. Model verification tests were conducted with these cutting force coefficients. These tests demonstrate that the predicted forces are within 5% of experimentally measured forces. Simulated results are also shown for predicting dynamic cutting forces and static/dynamic tool deflection. The second section of the paper discusses how the modeling methodology can be applied for feed rate scheduling in an industrial application. A case study for process optimization of machining an airfoil-like surface is used for demonstration. Based on the predicted instantaneous chip load and/or a specified force constraint, feed rate scheduling is utilized to increase metal removal rate. The feed rate scheduling implementation results in a 30% reduction in machining time for the airfoil-like surface.

2000 ◽  
Author(s):  
T. Bailey ◽  
M. A. Elbestawi ◽  
T. I. El-Wardany ◽  
P. Fitzpatrick

Abstract This is the second part of a two-part paper presenting a new methodology for analytically simulating multi axis machining of complex sculptured surfaces. The first section of this paper offers a detailed explanation of the model calibration procedure. A new methodology is presented for accurately determining the cutting force coefficients for multi-axis machining. The force model presented in Part I of this paper is reformulated so that the cutting force coefficients account for the effects of feed rate, cutting speed, and a complex cutting edge design. Experimental results are presented for the calibration procedure. Model verification tests were conducted with these cutting force coefficients. These tests demonstrate that the predicted forces are within 5% of experimentally measured forces. Simulated results are also shown for predicting dynamic cutting forces and static/dynamic tool deflection. The second section of the paper discusses how the modeling methodology can be applied for feed rate scheduling in an industrial application. A case study for process optimization of machining an airfoil-like surface is used for demonstration. Based on the predicted instantaneous chip load and/or a specified force constraint, feed rate scheduling is utilized to increase metal removal rate. The feed rate scheduling implementation results in a 30% reduction in machining time for the airfoil-like surface.


Author(s):  
Han Ul Lee ◽  
Dong-Woo Cho ◽  
Kornel F. Ehmann

Complex three-dimensional miniature components are needed in a wide range of industrial applications from aerospace to biomedicine. Such products can be effectively produced by micro-end-milling processes that are capable of accurately producing high aspect ratio features and parts. This paper presents a mechanistic cutting force model for the precise prediction of the cutting forces in micro-end-milling under various cutting conditions. In order to account for the actual physical phenomena at the edge of the tool, the components of the cutting force vector are determined based on the newly introduced concept of the partial effective rake angle. The proposed model also uses instantaneous cutting force coefficients that are independent of the end-milling cutting conditions. These cutting force coefficients, determined from measured cutting forces, reflect the influence of the majority of cutting mechanisms involved in micro-end-milling including the minimum chip-thickness effect. The comparison of the predicted and measured cutting forces has shown that the proposed method provides very accurate results.


Author(s):  
S. Rekers ◽  
O. Adams ◽  
D. Veselovac ◽  
F. Klocke

Due to lightweight construction numerous parts in turbomachinery industry with aerodynamic properties exhibit thin-walled features. Typical examples are compressor blades or turbine blades. Finish-milling depicts a stage of the manufacturing process of these parts with significant value creation. A major limitation of productivity is process stability in terms of self-excited or forced vibration. Different simulation approaches attempt determining a priori the process stability to avoid a bad surface quality, accelerated tool wear, tool breakage or scrapped parts. One distinctive part of these simulations is a cutting force model which incorporates material and tool dependent coefficients. The simulation accuracy directly depends on the exactness of these coefficients. Usually, these coefficients are identified experimentally from cutting force measurements with piezoelectric sensors, whose transmissibility is nonlinear. In this paper a multidimensional stationary inverse filter for compensating the influence of the nonlinear transmissibility of force sensors is presented. In a subsequent step, a Levenberg–Marquardt algorithm is used to identify cutting force coefficients from filtered force measurements. The functionality of the filter is validated by comparing highly nonlinear and almost linear piezoelectric force measurement sensors connected in series during finish-milling experiments. The accuracy of the identified cutting force coefficients is assessed by comparing cutting force simulations to measurements.


2019 ◽  
Vol 13 (3) ◽  
pp. 232-240
Author(s):  
Zhixin Feng ◽  
Meng Liu ◽  
Guohe Li

Background: Calibration of cutting coefficients is the key content in modeling a mechanistic cutting force model. Generally, in modeling cutting force for ball end milling, the tangent, radial and binormal cutting force coefficients are each considered as a polynomial, respectively. This fact is due to the dependency between the cutting force coefficients and the cutting edge inclination angle which is variable in ball-end mills. Objective: This paper presents an approach to determine the polynomial cutting force coefficients. Methods: In this approach, the cutting force coefficients are expressed as explicit linear equations about the average slotting forces. After analysis of the least square regression method which is utilized in the cutting coefficients evaluation, the principle of cutting parameters choice in calibration experiment and the relationship between the order of polynomial and the number of experiments are presented. Besides, a lot of patents on identification of polynomial cutting coefficients for milling force model were studied. Results: Finally, a series of semi-slotting verification cutting tests were arranged, the measured force agrees well with the predicted force, which demonstrates the effectiveness of this approach. Conclusion: Based on the calibration method proposed in this paper, the cutting coefficients can be determined through (m+2) slotting experiments for m-degree shearing coefficients polynomial theoretically.


2005 ◽  
Vol 127 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Jeong Hoon Ko ◽  
Dong-Woo Cho

Application of a ball-end milling process model to a CAD/CAM or CAPP system requires a generalized methodology to determine the cutting force coefficients for different cutting conditions. In this paper, we propose a mechanistic cutting force model for 3D ball-end milling using instantaneous cutting force coefficients that are independent of the cutting conditions. The uncut chip thickness model for three-dimensional machining considers cutter deflection and runout. An in-depth analysis of the characteristics of these cutting force coefficients, which can be determined from only a few test cuts, is provided. For more accurate cutting force predictions, the size effect is also modeled using the cutter edge length of the ball-end mill and is incorporated into the cutting force model. This method of estimating the 3D ball-end milling force coefficients has been tested experimentally for various cutting conditions.


2015 ◽  
Vol 1115 ◽  
pp. 55-58
Author(s):  
Wan Mohd Azlan Nowalid ◽  
Muhammad Adib Shaharun ◽  
Ahmad Razlan Yusoff

The cutting force is the main important factor contributing the machined work piece surface and in determining the acceptable cutting parameters for high productivity in metal cutting industries. The prediction of cutting force coefficients of materials were calculated from the average cutting force model contributing to the constants of cutting force coefficients. In this study, experimental investigation is conducted to determine the cutting force coefficients in the average cutting force model, by identifying cutting force coefficients with different lubrication conditions such as dry, flood and minimal lubrication conditions and cutting speeds. A series of slot milling experiments are measured the milling forces by fixing the spindle speeds and radial/axial depths of cutting and linearly varying the feed per tooth. Using linearly fitting the experimental data, the tangential and radial milling force coefficients are then computed. The achieved results showed that the changing of spindle speed and different lubrication conditions affecting the milling force coefficient.


2013 ◽  
Vol 774-776 ◽  
pp. 1174-1180
Author(s):  
M. N. Islam ◽  
A. Pramanik ◽  
A. K. Basak

This paper describes the development of an off-line feed rate scheduling technique based on a mechanistic cutting force model. The proposed technique was developed for an end milling operation. The surface area of the workpiece was divided into a number of segments, and the resultant cutting force at each discrete segment was determined using One Path Analysis software. The calculated resultant cutting force was applied to the feed rate scheduling. Experimental results clearly showed that the implementation of feed rate scheduling reduces machining time considerably and that as the number of segments increases, the effectiveness of the feed rate scheduling increases.


Sign in / Sign up

Export Citation Format

Share Document